1. Field of the Invention
This invention generally relates to closures for openings in building structures, and more specifically, to closures which are wind-resistant, such as a wind-resistant overhead door.
2. Background of the Invention
Closure devices for protecting openings in building structures, such as doors and windows, are frequently relied upon not only to provide security for the building structure by preventing unauthorized access to the structure, but are frequently also relied upon to protect the structure from severe natural climatic conditions. To the extent that doors and windows are made of glass, these are practicularly susceptible to certain climatic conditions, in particular hurricanes, cyclones and tornadoes. Glass which is frequently used to close openings in building structures are not only susceptible to being destroyed by flying debris during such adverse climatic conditions, but can also be destroyed as a result of dynamic and/or static air pressure differentials on the two sides of the windows, doors or the like. As a result of the dangers posed by these naturals climatic conditions, a number of States and local governments have enacted rules and relations in order to prevent or minimize damage. The State of Florida, for example, has enacted such relations and building codes due to the frequent occurrences of hurricanes in a number of counties in Florida, such as Dade and Broward counties.
One approach to ameliorate the problem has been to use shutters which are hingedly mounted on each side of the opening of the structure. However, such shutters, to be effective, have been made of heavy materials such as steel, are not conducive for automatic operation and are relatively expensive. Rolling, slatted doors and shades have also been used. These are typically rolled up in a coil at the top of the opening and unrolled to cover the entire opening exteriorly of the glass windows and doors. While such rolling closures have been effective to prevent impact by flying debris, they typically flex or bend when subjected to positive or negative pressures on the outside of the structure. However, such bending or flexing of the slats outside of the plane of the building structure effectively shortens the lengths of these slats by moving the ends inwardly, particularly on the sides and on the bottom of the door. While some known designs have attempted to limit the lateral inward movements of the ends of the slats to thereby prevent excessive bowing or flexing of the slats outside the plane of the rolling closure, these have not prevented excessive upward deflection of the lowermost slat due to the cumulative flexing of the intermediate slats, particularly at the central region or at points of the closure slats most remote from the lateral or anchored points. Such bending or flexing, therefore, creates an opening at the bottom of the slatted closure. This opening, if excessive, can be sufficient to create positive or negative pressure conditions between the slatted closure and the glass components of the window or door. Unless such bending or flexing is controlled, therefore, damage can still be caused by a severe hurricane, tornado or the like.